Getting started

Project layout:

my-plot-app/
├── CMakeLists.txt
├── main.cpp
└── qml/
    └── Main.qml

1. Add QAccelPlot to the build

Create CMakeLists.txt:

cmake_minimum_required(VERSION 3.16)

project(MyPlotApp VERSION 1.0 LANGUAGES CXX)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

find_package(Qt6 6.2 REQUIRED COMPONENTS Core Gui Quick ShaderTools)

include(FetchContent)
FetchContent_Declare(
    QAccelPlot
    GIT_REPOSITORY https://github.com/michalgrabarczyk/QAccelPlot.git
    GIT_TAG v0.5.0
)
FetchContent_MakeAvailable(QAccelPlot)

qt_add_executable(MyPlotApp MANUAL_FINALIZATION
    main.cpp
)

set_source_files_properties(qml/Main.qml PROPERTIES QT_RESOURCE_ALIAS Main.qml)
qt_add_resources(MyPlotApp "app_qml"
    PREFIX "/app"
    FILES qml/Main.qml
)

target_link_libraries(MyPlotApp PRIVATE
    Qt6::Core
    Qt6::Gui
    Qt6::Quick
    QAccelPlot::QAccelPlot
)

qt_import_qml_plugins(MyPlotApp)
qt_finalize_executable(MyPlotApp)

• QAccelPlot::QAccelPlot links the library and its static QML plugin. qt_import_qml_plugins() must run before qt_finalize_executable().
• ShaderTools compiles the curve shaders at build time.
• As a subproject, QAccelPlot's examples, tests, and install rules default to off.

Windows: launching from Explorer

Windows has no build RPATH. To start the application outside the IDE, deploy the Qt runtime beside it by appending:

if(WIN32)
    find_program(MY_PLOT_APP_WINDEPLOYQT
        NAMES windeployqt
        HINTS "${Qt6_DIR}/../../../bin"
        REQUIRED
    )

    add_custom_command(TARGET MyPlotApp POST_BUILD
        COMMAND "${MY_PLOT_APP_WINDEPLOYQT}"
            --qmldir "${CMAKE_CURRENT_SOURCE_DIR}/qml"
            --no-translations
            "$<TARGET_FILE:MyPlotApp>"
        COMMENT "Deploying the Qt runtime beside MyPlotApp"
        VERBATIM
    )
endif()

To use a local checkout, replace the FetchContent block with:

add_subdirectory(path/to/QAccelPlot ${CMAKE_BINARY_DIR}/QAccelPlot)

The second argument is required when the checkout is outside the application's source tree.

2. Create the plot

Create qml/Main.qml:

import QtQuick
import QAccelPlot as QAccelPlot

Window {
    width: 800
    height: 500
    visible: true
    title: "QAccelPlot example"

    QAccelPlot.Plot {
        id: plot
        anchors.fill: parent
        legendVisible: false

        xAxis: QAccelPlot.Axis {
            viewportMin: 0
            viewportMax: 10
            label: "Time (s)"
        }

        yAxis: QAccelPlot.Axis {
            viewportMin: -1.2
            viewportMax: 1.2
            label: "Amplitude"
            labelPadding: 34
        }

        QAccelPlot.LineCurve {
            objectName: "curve"
            xAxis: plot.xAxis
            yAxis: plot.yAxis
            color: QAccelPlot.Colors.dark.seriesPrimary
            lineWidth: 2
        }
    }
}

Every series needs an X and a Y axis. viewportMin and viewportMax set the visible range. A rescale fits the viewport to the data of the attached series.

3. Supply data from C++

Create main.cpp:

#include <QAccelPlot/series/LineCurve.hpp>

#include <QGuiApplication>
#include <QQmlApplicationEngine>

#include <vector>

int main(int argc, char* argv[])
{
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/app/Main.qml")));

    auto* root = engine.rootObjects().value(0);
    auto* curve = root
        ? root->findChild<QAccelPlot::LineCurve*>(QStringLiteral("curve"))
        : nullptr;
    if (!curve) {
        return -1;
    }

    const std::vector<double> times { 0, 2.5, 5, 7.5, 10 };
    const std::vector<double> amplitudes { 0, 0.8, -0.6, 0.4, 0 };
    curve->setData(times, amplitudes);
    return app.exec();
}

Public headers are included with the QAccelPlot/ prefix, for example <QAccelPlot/series/LineCurve.hpp>.

setData() takes separate X and Y vectors and suits small, static data. For large or streaming data, see the Performance guide.

4. Configure and build

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build --config Release

Add -DQACCELPLOT_USE_QT_PRIVATE_API=OFF when private Qt headers are not installed; see texture upload modes.

Default interaction

• Drag inside the plot area to pan all attached axes.
• Use the mouse wheel over the plot to zoom all axes around the mouse pointer.
• Use the mouse wheel over an individual axis to zoom only that axis.
• Enable rectangleZoom.enabled for Ctrl + left drag rectangle zoom. See Rectangle zoom.
• Double-click the plot to rescale all axes to their data ranges.
• Double-click an axis to rescale that axis only.

See Troubleshooting for common setup issues.